Small threaded connections: Recommendations for design and testing

摘要

This report describes how small threaded fasteners should be used in threaded connections. Considerable test experience gives many insights into how small threaded fasteners should be used. The test evidence is summarized in this report. The test methods and procedures are described for tension tests to determine strength and ductility. Small threaded fasteners have been used successfully for many years in Sandia applications. Problems have been encountered in manufacturing parts using three fasteners. This report addresses these manufacturing problems and offers recommendations in five areas: (1) design and layout of threaded connections, (2) required depths for tapped holes, (3) characteristics of mating (clamped) surfaces, (4) tensile strength testing procedures and lengths of engagement needed to achieve the full tensile strength of these small fasteners, and (5) installation procedures.